# ---
# title: 596. Classes More Than 5 Students
# id: problem596
# author: Tian Jun
# date: 2020-10-31
# difficulty: Easy
# categories: 
# link: <https://leetcode.com/problems/classes-more-than-5-students/description/>
# hidden: true
# ---
# 
# There is a table `courses` with columns: **student** and **class**
# 
# Please list out all classes which have more than or equal to 5 students.
# 
# For example, the table:
# 
#     
#     
#     +---------+------------+
#     | student | class      |
#     +---------+------------+
#     | A       | Math       |
#     | B       | English    |
#     | C       | Math       |
#     | D       | Biology    |
#     | E       | Math       |
#     | F       | Computer   |
#     | G       | Math       |
#     | H       | Math       |
#     | I       | Math       |
#     +---------+------------+
#     
# 
# Should output:
# 
#     
#     
#     +---------+
#     | class   |
#     +---------+
#     | Math    |
#     +---------+
#     
# 
# 
# 
# **Note:**  
# The students should not be counted duplicate in each course.
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
